Private Integrated Services Network (PISN) - Addressing (ISO/IEC 11571:1998, modified) (Endorsement of the English version EN 300189 V 1.2.1(1999-11) as German standard)— 1 стр.
Private Integrated Services Network (PISN) - Specification, functional models and information flows - Control aspects of circuit mode basic services [ISO/IEC 11574 (1994) modified]; English Version EN 300171 V 1.2.1 (1997.09)— 14 стр.